Avalanche Forecast

Issued: Feb 24th, 2020 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Deep Persistent Slabs.

Avalanche Canada JMackenzie, Avalanche Canada

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A bit of new snow has refreshed the skiing. Watch for buried wind slabs in steep terrain, as these are widespread at upper elevations. Be aware of changing conditions as winds on Tuesday may form fresh surface wind slabs.

Summary

Confidence

High -

Weather Forecast

Tuesday should bring a mix of sun and cloud with temperatures reaching a high of -7 in the Alpine. Winds will be moderate from the NW, switching to strong from the West later in the day. Wednesday will also bring a mix of sun and cloud with possibly a few flurries.

Avalanche Summary

Nothing new today.

Snowpack Summary

Up to 10cm of low density new snow in the past 24 hours from convective flurries. This snow overlies a variety of previous surfaces including wind slabs in the Alpine and sun crust on solar aspects. The previously formed wind slabs in the Alpine and open areas at Treeline are quite widespread and variable in depth and density. Good quality skiing today at all elevations. Snow profile today at 2200m confirms a strong midpack, but still 40cm of facets and depth hoar on the ground. Stability tests indicate an easy shear under the recent snow, and a hard shear on the basal facets. 

Terrain and Travel

  • Avoid convexities, steep unsupported terrain and rocky outcroppings.
  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
  • Watch for areas of hard wind slab on alpine features.

Problems

Wind Slabs

An icon showing Wind Slabs

The widespread wind slabs are now hidden under 10cm of fresh low density snow. These are primarily a concern in steep, convex and unsupported terrain. Thin areas may also be trigger points. As winds pick up speed from the NW on Tuesday, watch for fresh wind slabs on E through S aspects.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

This problem is still difficult to trigger, but snowpack stability tests today indicate a failure in the basal facets. Any resulting avalanche will be large and destructive.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1.5 - 3

Valid until: Feb 25th, 2020 4:00PM

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